Abstract
OBJECTIVES: The goal of this study was to investigate the relationship of body mass index (BMI) and its 25-year change to left ventricular (LV) structure and function. BACKGROUND: Longstanding obesity may be associated with clinical cardiac dysfunction and heart failure. Whether obesity relates to cardiac dysfunction during young adulthood and middle age has not been investigated. METHODS: The CARDIA (Coronary Artery Risk Development in Young Adult) study enrolled white and black adults ages 18 to 30 years in 1985 to 1986 (Year-0). At Year-25, cardiac function was assessed by conventional echocardiography, tissue Doppler imaging (TDI), and speckle tracking echocardiography (STE). Twenty-five-year change in BMI (classified as low: <27 kg/m(2) and high: ≥27 kg/m(2)) was categorized into 4 groups (Low-Low, High-Low, Low-High, and High-High). Multiple linear regression was used to quantify the association between categorical changes in BMI (Low-Low as reference) with LV structural and functional parameters obtained in middle age, adjusting for baseline and 25-year change in risk factors. RESULTS: The mean BMI was 24.4 kg/m(2) in 3,265 participants included at Year-0. Change in BMI adjusted for risk factors was directly associated with incipient myocardial systolic dysfunction assessed by STE (High-High: β-coefficient = 0.67; Low-High: β-coefficient = 0.35 for longitudinal peak systolic strain) and diastolic dysfunction assessed by TDI (High-High: β-coefficient = -074; Low-High: β-coefficient = -0.45 for e') and STE (High-High: β-coefficient = -0.06 for circumferential early diastolic strain rate). Greater BMI was also significantly associated with increased LV mass/height (High-High: β-coefficient = 26.11; Low-High: β-coefficient = 11.87). CONCLUSIONS: Longstanding obesity from young adulthood to middle age is associated with impaired LV systolic and diastolic function assessed by conventional echocardiography, TDI, and STE in a large biracial cohort of adults age 43 to 55 years.